possible starter problem?

When starting my car within the last few days, the start will sometimes sound horrible. Sometimes it will start fine. You know that sound you get from a start when the car won't start, the sorta high pitched, metal scraping noise? Well, I get that, but it will actually turn over, and start, but may take a few tries. The sounds, seems really clunky along with the high pitched sound, but that may just be because it is actually turning over and trying to start.

What's the best way to tell where this problem lies? I bought this bosch starter 4 years ago to diagnose why the car would intermittantly start back then, but the diagnosis then was just bad connections on the battery cables.

Ideas? Thanks.